Process for doing away with blow-holes and like flaws in castings.



- PATENTBD SEPT. 17, 1907.

- APE. MBNNE. PROCESS FOR DOING AWAY wmi BLOW HOLES AND LIKE FLAWS IN GASIIINGS.

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ammto'c Witmwwo UNITED STATES PATENT OFFICE.

ADOLPH EliNST MENNE, OF OREUZTHAL, GERMANY, ASSIGNOR TO THE FIRM OF GzjLN- MUSENER BERGWERKS AKTIEN VER'EIN, OF OREUZTHAL, GERMANY.

PROCESS FOR DOING AWAY BLOW-HOLES AND LIKE FLAWS IN CASTINGS.

No. 866,497. Specification of Application filed January 9 i To all whom it may concern:

Be it known that I, Anorlrn ERNST MENNE, a subject of the German Emperor, and a resident of Greuzthal, Westphalia, Germany, have inventednew and useful Improvements in Processes for Doing Away with Blow- --Holes and Like Flaws in Castings. of which the following is a specification.

Myinvention relates to a process for doing away with blow holes, and similar hollows in castings by means of an oxidizing gas or gases. It is particularly applicable to steel castings, and the oxidizing gas which I prefer to use is pure oxygen, or oxygen mixed with a small proportion of air or hydrogen.

Heretoiore it has been proposed to melt down the tops of ingots by means of an electric arc after a partial crust has formed, in order to doaway with blow holes, but it is essential in such operations that the application of the are be to the underside of the ingot in order that the molten metal may run out. In other words, such operations require that the hot ingot be turned upside down before the arc is applied, and if the advantages attending the use 0i carbon electrodes are to be secured, then the disadvantage of hardening the molten metal by the addition of carbon thereto encountered. Furthermore, a very large arc with its attendant large generating plant and other apparatus must be employed if a a great speed in themelting is to be obtained. Also, I

I heretofore encountered in doing away with blow holes,

ies

and to that end it consists in suitably placing the ingot preferably with its top end or head uppermost, and in employing a jet of oxygen under considerable pressure and in sufilcient' volume to burn out, as well as eject the molten metal, all as more particularly stated below.

In the drawing, the figure represents a casting with'a blow hole therein, an-oxyhydrogen blow pipe for-meltingthe upper part of the casting to reach the blow hole,-and a ladle for supplying' additional ;molten metal. .45

It is well known in making large castings, especially of iron c! steel, blow holes are=likely to form more especially-at ornear'the top of the same, and these blow holes will'forni even while the interior of the casting is still at a yellow heat. In carrying out my invention ta, do away with such blow holes either by remelting the entire top of the casting, or else by melting away a portion of the casting so as to reach the blow hole, in both cases using the gas. under considerable pressure, and

then I may pour in additional molten metal.

- -66 a represents in section a casting, b, a blow hole near .1905. seen u 240.362.

the upper part thereof, and c an oxyhydrogen blow pipe consisting of a pipe d providedwith a cock 0 for supply ing hydrogen, and a pipe f provided with'a g for supplying oxygen, the pipe f leading into thainterior of H the piped. 1

It represents a ladle adapted to be swung from any suitable support on bars 15..

j in dotted lines, represents the hole which it is intended to burn or melt to reach down to the blow hole b.

The oxyhydrogen blow pipe is of course movable. Instead of using an oxyhy'drogen blow pipe, the top 0! the casting a may be heated by placing fuel thereon, and a current of oxygen directed thereupon.

The stream or jet of oxygen gas directed for a time upon the surface of the casting, while said casting is setting, has for its object first either to keep the upper part of the casting liquid by means of the heat generated by the partial combustionof the steel, or to make it liquid again in orderthat it will flow into the holes which have formed, or secondly, to bore through the already rigid can then be filled up by pouring in an additional supply of molten metal. The surface of the steel is often still so hot that .the oxygen ignites the steel. If this is not the case, the combustion of the steel must first be started in some suitable manner, as by the oxyhydrogen blow pipe.

After the 'combustionis-well started, the supply of hydrogen is wholly or partially cut off in the pipe d; so that'the oxygen issues through the inner tube in large excess, or even alone. oftentimes the oxygen must be under a high pressure, even as high as 30 atmospheres in order to throw up the melted-mass around the point where the stream of oxygen strikes the casting. As the steel burns, it forms an oxid Fe O and experiments slag, so that on subsequently pouring in additional molten metal, a perfect weld or sweating takes place on the walls of the hollow By means of this process only small head s, orin favorable cascs no heads at all, are required.

I fi nd it desirable in most casesto heat the oxygen before it is delivered upon the surface of the casting.

What I claim as my invention, and desire to secure by Letters Patent, is:-

1. A process for doing away with hollows ln castings, conslstlng in suitably placing the same then applying an oxidizing gas under pressure to the top surface of the castlng then suitably startingthe combustion of the gas and then partially igniting and meltlng the mater-[a1 of the surface in order to prepare a way to the hollow which have shown that theresulting oxid rises as a thin liquid coating and ejecting the material until the hollows are.

reached and then filling up said hollows with liquid metal, substantially as described.

2. A process for doing away with hollows In costings, gonslstlng ln suitably placing the castlng then applying and igniting an oxidizing on under sumclent pressureto the top surface part at the said casting to eject the burned \the cfisting are exposed and their walls are at a suificient tem iera tnre to permit a good weld with any suitable molten'me'tal that mpy'be poured into the same, and in subsequentlylpouring molten metnlinto said hollows and I filling theniumsuhstentialiy asdescribed.

3. 41ml ior doin'g away with hollow; .lncastingmkl consisting in preliminarily heating and igniting an oxdizlng gas andin suitably placing the casting and npplyin'g tlie ignited gas to the top surtace of the Casting at a pressure suflicientto ejet the burned and molten metal until the hollows are reached, and their walls ate at a tempera ture and in a condition suitable for welding and then pour- -lng in molten metal until said hollows are filled, substantially as desq 'ibed.

-. .Witnesse's :9 p a n 4.,' A process for doing away with hollows in castings,

consisting in suitably pia'cing the'casting, and heatingnp the surfaceot the'aame, then in applying ogidizing gaei to thetop surface or saidcasting under a pressure sufficient to eject the burned and noltenmetai, until the hollows 20 ate reached and until the walls of the same are in a suitable welding condition, and finally pouring molten metal into said holiows and permitting the same to become; welded to the casting, substantiallyEs'descrlbedi In testimony whereof, I have signed my name to this "25 specification, in the presence 01'. two subscribing witnesses.

ADOLPB ERNST MENNE.

' WILLIAM Kungzhn, v 

